Rust inhibiting soluble oil composition



3,057,799 RUST INHIBITING SOLUBLE 01L COMPOSITION John E. Wilkey, Euclid, Ohio, assignor to Sea Gull Lubri carats, Inc., ,leveland, Ohio, a corporation of Ohio No Drawing. Filed June 2, 1959, Set. No. 817,489 8 Claims. (Cl. 252-334) This invention relates to emulsifiable oil compositions suitable for use as rust preventative concentrates to prevent corrosion of ferrous metal surfaces. The invention particularly relates to the treatment of scrap formed in precision metal machining operations to prevent the formation of rust on the surfaces of the scrap.

In the past, a blend of rust inhibitor and petroleum solvent has been applied to machined ferrous metal surfaces to prevent corrosion thereof. However, water is now widely used as the solvent for the rust inhibitors since the petroleum solvent gave off fumes, wa highly inflammable and thus was expensive and very hazardous to use. Even with the use of Water as a solvent, certain problems remained in the treatment of machined metal surfaces to prevent corrosion. Most oil-in-water emulsions were relatively expensive since the oil could be diluted by only a relatively small amount of water. Only 1 part by weight of the oil could be diluted by emusification in only about 10 parts by weight of wate and still retain the ability to inhibit rusting of the machined surfaces. In addition, such o-il-in-water emulsion systems (as well as other rust inhibiting systems including non-oily synthetic coolants or sodium nitrite/amino alkanol systerns) leave undesirable deposits on the machined metal surfaces and also tend to deoil the machine.

It is important for economical operation that the scrap formed during the machining of metal parts be resmelted in a cupola or the like to thereby recover the metal. When deposits or scum are left on th machined surfaces, the cost of recovering the metal is greatly increased since all the scum or other deposits, such as sodium nitrite in the case of the sodium nitrite/amino alkanol compound system, must be burned off and eliminated in the flue gas in order to elficiently smelt the metal scrap.

Another disadvantage of the present oil-in-water emulsion systems is that. due to the relatively high amount of oil used, the deposit of oil formed on the ferrous surfaces is relatively thick and must be burned off in the cu ola as a heavy smoke in order to effectively recover the scrap metal.

It is therefore an object of the present invention to provide a rust inhibiting water soluble oil composition which can be diluted as high as 150 to 1 or even 200 to l and still prevent the corrosion of machined metal surfaces.

it is an object to provide an improved rust inhibiting nil composition which can be emulsified in water in relatively high dilutions and still prevent the formation of iLlS't on machined metal surfaces without de-oiling the machine or leaving undesirable deposits on the machined pieces or scrap.

it is an object to provide a method of making an emulsitiablc oil composition that will inhibit rusting of ferrous metals even at relatively high dilutions.

It is object of the present invention to provide an oil-in-water emulsion that will inhibit rusting of ferrous metals by emulsifying an oil concentrate in water at a dilution as high as 200 to 1, the cil-ia-water emulsion l-=2ing effective to prevent corrosion of machined metal surfaces without de-oiling the machine or without depositing scum on other undesirable material on the machined metal surfaces.

it is an object to provide a method of making an oilin-water emulsion which will prevent corrosion of ferrous metals without leaving deposits on the surfaces of the metal to thereby aid in economical recovery of the machined metal scrap, turnings and borings.

The present invention provides an improved rust inhibiting oil composition which can be emulsified in water at a dilution rate as high as 200 parts by weight of water to 1 part of oil. Evan at such a high dilution, the emulsifiable oil composition is effectiv in preventing corrosion of machined ferrous metal surfaces without de-oiling the precision metal forming machine or without leaving undesirable deposits or scum on the machined surfaces. In addition, great savings are obtained by the relatively low quantity of oil required to make the rust preventative oilin-water emulsion.

While the preferred range of dilution of the emulsifiable oil composition in water is about to 1 to /1 for most commercial applications, the benefits of the present invention generally can be obtained by using dilutions as high as 200/1 or even slightly higher.

The present invention provides an emulsifiable oil concentrate that will inhibit rusting of ferrous metals comprising (1) about 70 to 80 parts by weight of a mineral oil (2) about /2 to 5 parts by weight of an alkyl phosphat providing the alkyl phosphate has a neutralization number of at least about 190 milligrams of KOH per gram and providing the alkyl radical has about 10 to 24 carbon atoms and (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number of a particular range, namely, about 9.5 to 12.5 milligrams of KOH per gram.

It has been found that the addition of the above mentioned alkyl phosphate prevents the rusting of scrap ferrous metals at even a dilution as high as 200/1 (200 parts water to 1 part of oil). It, apparently, is highly important that the alkyl phosphate have a neutralization number of at least about 190 milligrams of KOH per gram. Alkyl phosphates having a neutralization number of even as high as about have been found to provide no rust inhibiting action. While a neutralization number of about milligrams of KOH per gram is suitable for many applications, it is greatly preferred that the neutralization number of the alkyl phosphate be at least 200 milligrams of KOH. The best corrosion inhibiting action is provided when the alkyl phosphate has a neutralization number in the range of 270 to 350. On the other hand when the neutralization number is higher than about 400, apparently the phosphate is too acidic, some of the compatibility of the phosphate for the system is lost, and little rust inhibiting action is obtained. Thus when no alkyl phosphate is used or when an alkyl phosphate is used not having the necessary acidity or not having the proper length of hydrocarbon (alkyl or alkenyl) chain, rusting of ferrous metals will not be prevented even at concentration of 30/1 or 50/1 (weight ratio of water to oil concentrate).

The neutralization number, expressed as milligrams of KOH per gram, can be determined by either Federal Specification 5103.3, 1953, or ASTM 975-55 T. However, these methods contain extra steps in order to take care of a variety of compounded and used oils. We prefer to use a modification of Federal Method 5103.3. This consists of weighing approximately 10 grams of oil in an crlenmeyer flask, dissolving the oil in 50 ml. of neutralized isopropyl alcohol, warming the solution to about 50 C. and titrating with a half-normal KOH solution. The neutralization number, expressed as milligrams of KOH, is determined as follows:

Neutralization No.=ml KOH normality X 56.1 weight of sample It is believed that alkyl phosphate may be prepared by reacting about 1 to 3 moles, and preferably 1.2 to 2 moles, of a long chain alkyl alcohol having 12 to 24 carbon atoms with 1 mole of phosphorous pentoxide. Thus an alkyl phosphate that provides excellent results according to the present invention may be prepared by reacting long chain hydrocarbon alcohols such as dodecyl alcohol with P The resultant alkyl phosphate may be mono-alkyl substituted phosphoric acid, or a dior tri-substituted phosphoric acid or mixtures thereof. The alkyl phosphates of the present invention are preferably monoand di-substituted alkyl phosphates obtained by reacting a long chain alcohol such as octyl decyl alcohol, nonyl decyl alcohol, decyl alcohol, tridecyl alcohol, octadecyl alcohol and preferably dodecyl alcohol with P 0 or phosphoric acid to form generally mono-alkyl phosphates and di-alkyl phosphates in which the di-alkyl preferably forms a majority of the alkyl phosphate mixture. Suitable mono and di-alkyl phosphates used according to the present invention may be described by the general formula where R and R are residues the reaction of long chain alcohols having about 12 to 24 carbon atoms such as dodecyl alcohol and octadecyl alcohol with P 0 R and R may be residues of the same long chain alcohol or they may be residues of a mixture of long chain alcohols. While at least one of R and R' are preferably dodecyl alcohol, R and R may be a mixture of alkyl and alkenyl radicals, i.e., hydrocarbon radicals of to 24 carbon atoms such as those hydrocarbon groups sometimes termed coco which are derived from coconut oil. Thus, a di coco phosphate of 8 to 18 carbon atoms would designate a phosphate in which R and R are mixtures of hydrocarbons having 8 to 18 carbon atoms.

It has been found that the length of the alkyl radical is of some importance inasmuch as an alkyl chain of only 3 carbon atoms will not provide any rust inhibiting. On the other hand when the length of the alkyl chain becomes longer than 24 carbon atoms, the compatibility of the phosphate in the system is lost and the benefits of the present invention are not obtained.

As previously indicated, the mixture of alkyl phosphate should contain preferably a major portion of monoand di-alkyl phosphates in order to obtain a high enough neutralization number of at least 190 milligrams of KOH per gram. Another way of designating the acidity of the alkyl phosphate is by indicating the percent by weight of phosphorous in the alkyl phosphate. Generally, the alkyl phosphates should contain more than 5 percent phosphorous. When the acid content is only 5 percent phosphorous, it is too low to provide any benefits of the present invention. Although I do not wish to be held to any theory, apparently at least part of the corrosion inhibiting action is provided by the formation of ferrous phosphate coating on the surface of the machined metal. In any event, the acidity of the phosphate can be great since it has been found that neutral alkyl phosphates containing as high as about 20 percent phosphorous do not provide a rust inhibiting action. In general, the percent phosphorous in the alkyl alcohol/P 0 reaction product should be about 7 to percent phosphorous, although the best results are obtained at about 8 to 12 percent phosphorous.

While it has been previously indicated that the alkyl phosphate generally can be used in amounts of /2 to 5 parts by weight, the best results are obtained by using about 1 to 3 parts by weight of the alkyl phosphate. Thus the preferred rust preventative concentrate comprises about 1 to 3 parts by weight of alkyl phosphate, about to 24 parts by weight of an emulsifier, and about 79 to 73 parts by weight of a mineral oil. Furthermore, in accordance with the present invention, the optimum formulation of the oil concentrate to be emulsitied in water is about 2 parts by weight of the alkyl phosphate, 23 parts by weight of the emulsifier and 75 parts by weight of the mineral oil.

It is also important that the emulsifier used to disperse the mineral oil in water have only a certain critical neutralization number range as previously discussed, the neutralization number range should be generally about 9.5 to 12.5 milligrams of KOH per gram although it is highly preferred for most applications that the neutralization number of the emulsifier being in the range of 10 to 12 milligrams of KOH per gram. When the emulsifier has a neutralization number of only 9, the surfaces of machined metal parts and scrap rust badly. Also, generally, if the neutralization number is too low, the emulsifier may separate from the oil or the emulsion may be too stable to provide appreciable rust inhibiting action.

As illustrative of the need for a proper emulsifier, a simple emulsifier system comprising an amine soap dissolved in oil will not work-either the oil will not emulsify or rusting will occur. A great many emulsifier formulations have been used but either the oil will not emulsify or rusting will occur unless the particular emulsifier hereinafter described is used and also providing it has the neutralization number previously discussed which for the best results is a range of about 10.5 to 11.5 milligrams of KOH per gram.

Apparently at least part of the unusual rust inhibiting action of the present invention is provided by the instability of the oil-in-water emulsion. When the oil emulsifier and water are mixed and an emulsion made by shaking or otherwise agitating the mixture, the emulsion is not stable and creaming occurs. Even though the emulsion is unstable, it inhibits rusting even at relatively high dilutions. Unfortunately though, the emulslon does leave some gummy scum on the surfaces of the scrap and machined metal parts.

It has been found that when borax is added in certain amounts to the oil-in-water emulsion, the emulsion is stabilized and, surprisingly, the parts will not rust even though as much as 200 parts of water is used per 1 part of oil. When borax is used, dilutions of l or even up to as high as 200/ l are commercially feasible.

Preferably about .2 percent to .7 percent of borax may be added to stabilize the emulsion based on weight of water. In general, however, the concentration of borax can be from 0.1 percent by weight to an amount above it solubility.

The pH of the emulsion is preferably about 6.8 before the addition of borax. The addition of the borax generally raises the pH of the oil-in-water emulsion from the initial pH of approximately 6.5 to 6.9 to about 9.2 to 9.4. Surprisingly, other alkaline materials or buffers such as carbonates, phosphates or silicates of sodium and potassium do not act as an emulsion stabilizer in the manner as does borax.

In the present invention, it is preferred that an alkyl amine be used to balance the oil so that it will emulsify readily in tap water. Suitable alkyl amines are polyhydroxy amines such as triethanolamine, tripropanolamine, and other trialkyloxy amines in which the alkyl radical has about 1 to 4 carbon atoms. Of the mono alkyl amines such as mono isopropanolamine, mono propanolamine, mono butanol amine and mono octanol amine, monoethanolamine provides the best stabilization for the emulsifiable oil concentrate used in the present invention.

Among the amino compounds (having ether or hydroxyl oxygen atoms) that are useful in assisting the emulsification of the oil are polyoxy amines which are generally formed by reacting l to 10 moles of an alkylene oxide and about 1 mole of a fatty amine or diamine hav ing 12 to 24 carbon atoms. The alkylene oxide used to form the polyoxy amine may be propylene oxide, butylene However, the preferred alkylene oxide is ethylene oxide. Suitable examples of the fatty amines or diamines used to make the polyoxy amines are N-duodecyl ethylene dismine, N-octodecyl ethylene diamine and N-tetradecyl propylene diamine. One mole of the above diamines is reacted with about 5 moles of ethylene oxide to form a preferred polyoxyamine.

It is thus seen that suitable amines for use as an oil balancing agent or emulsifying assisting agent for the oil are polyhydroxy amines and polyoxyamines having only nitrogen, hydrogen, carbon and oxygen atoms in their molecule. Further, their molecular chains have only nitrogen, carbon and oxygen atoms as chain atoms.

The emulsifying assisting amine is preferably used in amounts of about 0.05 to 0.5 percent by weight based on the weight of the oil concentrate. While in some cases, amounts as low as .01 percent provide at least some emulsifying action, it is preferred, for the best emulsifying action and rust inhibiting action, that a range of about .1 to .3 be used. Also, it has been found that 1 percent by weight of alkyl-amine is too much in most cases, and rusting will occur, the delicate physical and chemical balance of the emulsification system being lost.

A preferred method of making emulsifiable oil which will prevent the formation of rust on ferrous metals according to the present invention comprises the first step of dissolving an alkyl phosphate having a certain neutralization number as previously described in a non-viscous mineral oil having an A.P.l. gravity of about 28 to 33 and a viscosity of 40 to 80 S.S.U. at 100 degrees Fahrenheit. The above viscosity range is given in Saybolt Universal seconds. Secondly, after the alkyl phosphate is diluted in the above mineral oil, the emulsifier (having a certain neutralization number) is then added to the solution of alkyl phosphate in mineral oil and dissolved therein. Thirdly, the alkyl phosphate/emulsifier/mineral oil solution is then tested for emulsifying properties by adding a small amount, say grams, of the solution to 90 grams of water, shaking the oil concentrate and Water mixture, and then observing the emulsifying effect thereon. As a fourth step, sutficient amount of an emulsifying assisting amino compound such as monoethanolamine is added to the oil so that the oil will emulsify readily in tap water but will start to separate or cream after standing for about 10 minutes.

As a preferred fifth step, in order to prevent any undesirable formation of gum on the surface of machined metal parts and pieces of scrap, borax is added to the water and dissolved therein. Then the water, containing borax in solution, is used as the diluent for the rust inhibiting oil composition. In this fashion, ereaming of the emulsion is eliminated without sacrificing the unusual rust inhibiting action of the emulsion. The addition of borax improves the wetting ability of the emulsion and minimizes the accumulation of excess oil on the parts and the chips-all of which saves time and labor in the scrap salvaging operation.

Thus broadly stated, the present invention provides a method of making a rust inhibiting oil-in-water emulsion comprising the steps of mixing (a) about /2 to 5 parts by weight of an alkyl phosphate having a neutralization number of at least 190 milligrams of KOH per gram andin which the alkyl radical has about 10 to 24 carbon atoms, (b) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 and 12.5 milligrams of KOH per gram and (c) about 70 to 80 parts by weight of a mineral oil to form a rust inhibiting oil concentrate, (d) adding about 0.05 to 0.5% by weight based on the weight of concentrate of an emulsifying assisting amine, and (a) thereafter emulsifying one part by weight of said oil concentrate with about 20 to 200 parts by weight of water to form an oil-in-water emulsion.

Also as an important part of the present invention, the preferred method of forming an oil-in-water emulsion, in addition to the steps just described, includes the step oxide or mixtures thereof.

adding about 0.2 to 7 percent by weight of borax to the water before the oil-in-water emulsion is formed.

As previously indicated, the composition of the emulsifier itself is important in addition to the requirement that its neutralization number he in the range of 9.5 to 12.5 milligrams of KOH per gram. In accordance with the present invention, by far the best results are obtained with the following emulsifier composition:

As noted in the above table, the preferred emulsifier is a mixture of (1) mineral oil, (2) alkyl aryl sulphonates having a molecular weight of 420 to 520, (3) sulphonated castor oil, (4) tall oil, (5) an alkali hydroxide, and (6) coupling agents such as diethylene glycol and isopropyl alcohol.

Broadly stated, an emulsifier suitable for the present invention should have a neutralization number of 9.5 to 12.5 milligrams of KOH per gram and should comprise a mixture of a mineral oil, a non-ionic wetting agent (such as diethylene glycol), an anionic wetting agent (such as a mixture of an aryl alkyl sulphonate, sulphonated castor oil and tall oil) and a coupling agent such as isopropyl alcohol.

An emulsifier suitable for use in the present invention generally may comprise a mixture of about 10 to 20 parts by weight of a mineral oil, about 20 to 34 parts by weight of tall oil, about 1 to 10 parts by weight of an alkali hydroxide, about 2 to 12 parts by weight of water, about 27 to 37 parts by weight of an alkyl aryl sulphonate having the molecular weight in the range of about 300 to 600, about 0.1 to 8 parts by weight of sulphonated castor oil, about 0.5 to 5 parts by weight of an alkylene glycol, and about 3 to 12 parts by weight of a coupling agent.

The tall oil used in the emulsifier, as is well known, is obtained by acidifying the soap separating from the black liquor in the sulphate-cellulose kraft process for making wood into paper pulp. Tall oil has as its principle components about 46 to 50 percent by weight of resin acids (principally abietic acid) and 43 to 47 percent by weight of fatty acids (mainly ricinoleic acid) plus some relatively small amounts, 6 to 8 percent, of unsaponifiable materials, ash and moisture. The tall oil useful herein may be considered approximately a mixture of about equal parts of neutralized abietic acid and ricinoleic acid, although mixtures thereof are suitable in which each ingredient may be present in amounts of about 30 to 60 percent of the total weight. Abietic acid, C I-I O as is well known, is diterpene carboxylic acid and a constituent of common rosin. The abietic acid may be considered present in the form of the alkali metal salts of abietic acid having the general formula: CzoHzgOzM, where M is sodium or potassium. Also as is well known ricinoleic acid C H (OH).COOH is a fatty acid constituting a major portion of castor oil. Other suitable neutralized fatty acid and aromatic acid mixtures that can be used in place of the tall oil are mixtures of abietic acid, with oleic acid, lauric acid, and 2 ethyl hexoic acid.

As previously indicated, generally the tall oil is used in the emulsifier composition in the range of about 20 to 34 parts by weight and preferably is used in amounts of about 24 to 30 parts by weight as seen in Table I.

Another important ingredient of the emulsifier formulation is an alkali hydroxide. The alkali hydroxide is preferably potassium hydroxide, although other alkali metal hydroxides such as sodium hydroxide are also suitable. The alkali hydroxide generally is used in amounts of about 1 to 10 parts by weight per 100 parts by Weight of emulsifier although it is preferred that the potassium hydroxide be used in the amounts of about 2 to 8 parts by weight as noted in Table 1. Generally the potassium hydroxide is used in the form of a caustic potash water solution in which 4 or 5 parts of potassium hydroxide are dissolved in preferably 5 to 7 parts by weight of water, although water in the range of 2 to 12 parts by weight may be used.

Another important part of emulsifier formula is the purified petroleum sulphates having an average molecular weight preferably in the range of about 420 to 520, although an average molecular weight in the range of as low as 300 to as high as 600 may be useful to provide at least some of the benefits of the present invention. Some of the molecular weights of the individual petroleum or alkyl aryl sulfonates may be as low as 200 and as high as 800. For best results, alkali metal soaps of sulphonic acids derived from petroleum sources having an average molecular weight of 420 to 520 should be used. Of these alkali metal soaps, the sodium salt is particularly outstanding, although other alkali metal soaps such as those of potassium are useful.

The sulphonic acids used to form the alkali metal soaps may be derived from either petroleum or alkyl aromatic acids. Suitable alkyl aryl sulphonates are poly propyl benzene sodium sulphonate, poly propyl benzene potassium sulphonate, the sodium and potassium salts of didodecyl tolulene sulfonic acid, octa decyl naphthalene sodium sulfonate and poly propyl napthalene sodium sulphonate.

As previously indicated, the alkyl aryl sulphonate is generally used in the amounts of about 27 to 37 parts by weight or preferably 29 to 35 parts by weight as seen in the emulsifier formula set forth in Table I. It has been found that when the aryl alkyl sulphonates have an average molecular weight of more than 600, the compatability of the sulphonate for the system is lost and benefits of the present invention are lost.

As seen in Table I, for instance, a part of the emulsifier formula is sulphonated castor oil. This ingredient is generally used in amounts of about 0.1 to 8 parts by weight,

although the preferred range of turkey red oil or sulphonated castor oil is about 1.5 to 7.5 parts by weight. The turkey red oil, as well known in the art, generally is made by heating 100 parts of castor oil with about 15 or 25 parts by concentrated sulfuric acid at a temperature not exceeding about 30 C. The reaction product is first washed with water then with a solution of sodium sulphate. An alkaline hydroxide such as ammonium or sodium hydroxide is then added to the washed ricinoleosulfuric acid until it gives a clear solution with water, the resulting products being known commercially as sodaolein when NaOH is used as the alkaline hydroxide. Of the commercial sulphonated castor oils, the density generally varies from about 1.02 to 1.25 and they are miscible with water. A variety of turkey red oil may be prepared from olive oil derived from olives which have been allowed to become rancid and then oxidized by exposure to moisture and air. In any event, apparently the solvent and emulsifying properties of the neutralized castor oil sulfuric acid reaction products are important in preparing the emulsifier of the present invention. Other neutralized sulfonated oils of fatty acids having a hydrocarbon chain of about 12 to 20 carbon atoms may be used as all or part of the turkey red oil in the present invention. Other oils that may be used in place of the castor oil include are arachias, cotton-seed, cod and other fish oils, maize and neats-foot oils.

In the present invention, coupling agents are useful to emulsify the rust preventative base. The coupling agent is generally useful in amounts of about 3 to 20 parts by Weight and preferably is used in amounts of 4.5 to 16 parts by weight (see Table I in which the preferred range of diethylene glycol is given as 0.5 to 6 parts by weight and the range of isopropyl alcohol is given as 4 to 10 parts by weight. The preferred coupling agent composition comprises about 2 to 4 parts by weight of diethylene gly col or other alkylene glycol and about 6 to 8 parts by weight of isopropyl alcohol or other alkyl alcohol.

The coupling agents are preferably glycol ethers and poly glycol ethers having about 5 to 15 carbon atoms. It is important that the coupling agents evaporate at about the same rate as water in order to produce a film on the machined metal surfaces which will not emulsify in case water recondenses on it.

Suitable glycol ethers are ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, and propylene glycol monoethyl ether. Of the glycol ethers, ethylene glycol monobutyl ether is preferred, it being commercially available under the trade Butyl Cellosolve.

Suitable polyglycol ethers are the monomethyl, monoethyl, monopropyl, and monophenyl ethers of diethylene glycol and dipropylene glycol. A preferred polyglycol ether is Butyl Carbitol which is a trade name for diethylene glycol monobutyl ether.

Thus, suitable glycol ethers and polyglycol ethers have the general formula RO--X-OR, where R is hydrogen, an alkylol, or mixtures thereof and R is hydrogen, alkyl or aryl radicals, and where X is an alkylene radical or an alkylene oxide residue or a residue of a glycol ether such as diethylene glycol which has beenreacted with an alkyl alcohol. As previously indicated, other suitable coupling agents are diethylene glycol, dipropylene glycol, ethylene glycol, butylene glycol, pentylene glycol, neopentylene glycol, tetramethylene glycol and alkyl alcohols such as ethyl alcohol, isopropyl alcohol, and other alkyl alcohols preferably having 2 to 3 carbon atoms. In a similar manner, the suitable alkylene glycols such as ethylene glycol generally should have an alkylene group of from 2 to 5 carbon atoms.

.As indicated by the emulsifier formula set forth in Table I, the preferred coupling agent is a mixture of an alkylene glycol and an alkyl alcohol in which the alkylene glycol is present preferably in amounts of about 2 to 4,

parts by weight and the alkyl alcohol present in the amounts 6 to 8 parts by weight. However, generally the glycol may be present in the amounts of about .5 to 5 parts by weight and the alkyl alcohol or other coupling agents present in the amount of about 3 to 12 parts by weight. It is important that the correct amounts of the coupling agents be used since the system must be balanced.

Also, an important part of the emulsifier is the mineral oil. The mineral oil, of course, is used also as the oil used to be emulsified to form the rust inhibiting fluid. In general, a mineral oil may be used which is any refined distillate, whether of naphthenic or paraffinic origin. Generally a mineral oil, or preferably a light petroleum neutral oil, having a viscosity in the range of about 60 to 3000 S.U.S. at 100 F. may be employed, although it is preferred that the viscosity range be to 500 S.U.S. at F. Generally preferred for most rust inhibiting concentrates are acid-refined propane distillates from naphthenic base or Mid-Continent crudes. It is to be understood that the above described mineral oil or preferred light petroleum neutral oil is used both as the oil to be emulsified and as a component of the emulsifier formulation.

As to the emulsifier formulation, the mineral oil is generally used in amounts of about 10 to 20 parts of the emulsifier. It is highly preferred that the mineral oil (and particularly an oil having a viscosity range of about 90 to 150 S.U.S. at 100 F.) be used in amounts of about 12 to 18 parts by weight. See Table I. Also, as indicated in Table I, the optimum range of the mineral oil is about 15 parts by weight based on 100 parts total Weight of the emulsifier.

The following example illustrates the present invention:

Example 1 An oil-in water emulsion was made by dissolving 2 parts by weight of an alkyl phosphate in 75 parts by weight of a mineral oil. The alkyl phosphate used was the reaction product of dodecyl alcohol and P The phosphate contained phosphorous and had a neutralization number of about 270 milligrams of KOH per gram. The oil used as a solvent for the phosphate was a light petroleum neutral oil having a viscosity of about 70 S.U.S. at 100 F.

Next, an emulsifier, having a composition disclosed hereinafter, was mixed with the alkyl phosphate-oil solution and dissolved therein. Monoethanol amine was added in sufficient amount to form an unstable emulsion in the water. The amount of monoethanol amine used was 0.2 part by weight.

The rust inhibiting concentrate of this example, then, had the following composition:

TABLE II nus'r INIIIBITING CONCENTRATE Ingredients: Parts by weight Mineral oil 75 Alkyl phosphate 2 Emulsifier 23 Monoethanol amine 0.2

The emulsifier had a neutralization number of about 10.7 milligrams of KOH per gram and had a composition as follows:

TABLE III EMULSIFIER Ingredients: Parts by weight Mineral oil,.100 S.U.S. at 100 F Tall oil 27.1 Potassium hydroxide 4.5 Water 6.3 Sodium salt of a mixture of petroleum sulphonic acids having a molecular weight of about 450, the principal ingredient being polypropyl benzene sodium sulphonate 31.8 75% sulphonated castor oil 4.5 Diethylene glycol 3.2 Isopropyl alcohol 7.6

The above rust inhibiting concentrate (containing the oil with the alkyl phosphate and emulsifier dissolved therein) was then mixed with water at dilution ratios of 100 to l, 150 to 1, and 200 to 1 to form a seris of oil-inwater emulsions. The oil was found to emulsify readily in tap water. The emulsion started to separate or cream after standing for about 10 minutes. This emulsion, although unstable, was applied to scrap ferrous metal and was found to inhibit rusting of the surface. Even the emulsion formed with 200 parts of water to 1 part of rust inhibiting concentrate inhibited corrosion of the ferrous metal surfaces.

Example 2 A series of emulsions was made using the rust inhibiting oil concentrate of Example 1 with water at the weight ratios of water/oil of /1, 50/1, 100/1 and 200/1. In addition. 0.5 percent by weight of borax (based on the weight of water used) was added to each of the emulsions. The borax was used by adding it to the water before the oil-in-water emulsion was made. The addition of borax was found to make even the very dilute emulsions stable.

'to the surfaces of scrap from ferrous metal machiu 153 The oil-in-water emulsions of Example 2 wer ap operations. In each case corrosion of the ferrous metal surfaces was prevented.

Example 3 An emulsion was prepared with 30 parts of water to 1 part oil concentrate as described in Example 2 using the same amount of alkyl amine, emulsifier and borax, except that the alkyl phosphate was omitted from the emulsifier formulation altogether. Theemulsion was applied to ferrous metal scrap. Rusting of the surfaces was ap parent even as soon as 30 minutes after application of the emulsion.

By way of reviewing the test results described in the above examples, it is noted that the emulsions of Example 1 and Example 2 were effective in inhibiting corrosion of the metal surfaces even at high dilution. In addition, the emulsions of Example 2 left no scum on metal chips and thus are preferred for commercial applications over the emulsions of Example 1. The addition of borax apparently helped to stabilize the emulsion, improved its wetting ability, and minimized the accumulation of excess oil and water on the parts and chips.

In the examples described above, other alkyl phosphates and other emulsifiers as herein disclosed may be substituted in whole and part for the alkyl phosphates and the emulsifiers used, providing of course, that the alkyl phosphates have neutralization numbers in the critical neutralization number range previously described and providing that th emulsifiers also have neutralization numbers in the critical neutralization number range previously described. In addition, other emulsifying assisting amino compounds such as the alkyl amines previously described may be substituted for all or part of the monoethanolamine and other suitable mineral oils herein de scribed may be substituted for the particular mineral oil used in the examples.

It is to be understood that in accordance with the provisions of the patents statutes, variations and modifications of the specific invention herein shown and described may be made without departing from the spirit of the invention.

What is claimed is:

1. An emulsifiable oil composition that will inhibit rusting of ferrous metals comprising (1) about 70 to parts by weight of a mineral oil, (2) about /2 to 5 parts by weight of an alkyl phosphate having a neutralization number of about 270 to 350 milligrams of KOH per gram and in which the alkyl radical has about 10 to 24 carbon atoms and (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 to 12.5 milligrams of KOH per gram and comprising (a) about 10 to 20 parts by Weight of mineral oil, (b) about 22 to 32 parts by weight of tall oil, (0) about 1 to 10 parts by weight of an alkali metal hydroxide, (d) about 2 to 12 parts by weight of water, (e) about 27 to 37 parts by weight of an alkali metal soap of an alkyl aryl sulphonic acid having a molecular weight of about 300 to 600, (f) about 0.1 to 8 parts by weight of sulphonated castor oil, (g) about 0.5 to 5 parts by weight of an alkylene glycol, and (h) about 3 to 12 parts by weight of an aliphatic alcohol.

2. An emulsifiable oil composition comprising (1) about 70 to 80 parts by weight of a mineral oil, (2) about /2 to 5 parts by weight of an alkyl phosphate having a neutralization number of about to 400 milligrams of KOH per gram and in which the alkyl radical has about 10 to 24 carbon atoms, and (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 and 12.5 milligrams of KOH per gram and comprising (a) about 12 to 18 parts by weight of mineral oil, (b) about 24 to 30 parts by weight of tall oil, (0) about 3 to 9 parts by weight of water (d) about 29 to 35 parts by weight of an alkali metal salt of an alkyl aryl sulphonic acid having a molecular weight of about 420 to 520 (e) about /2 to 7 /2 parts by weight of sulphonated castor oil (I) about 0.5 to 6 parts by weight of an alkylene glycol in which the alkylene radical has about 2 to 5 carbon atoms, and (g) about 4 to 10 parts by weight of an aliphatic alcohol having 2 to 3 carbon atoms and one hydroxyl group.

3. An emulsifiable 'oil composition as defined in claim 2 in which the alkylene glycol is diethylene glycol and the aliphatic alcohol is isopropyl alcohol and the alkyl phosphate has a neutralization number of about 270.

4. An emulsifiable oil composition as defined in claim 2 in which the alkyl phosphate is a reaction product of P and dodecyl alcohol.

5. An emulsifiable oil composition comprising (1) about 70 to 80 parts by weight of a mineral oil, (2) about /2 to 5 parts by weight of an alkyl phosphate having a neutralization number of about 190 to 400 milligrams of KOH per gram and in which the alkyl radical has about to 24 carbon atoms, (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 and 12.5 milligrams of KOH per gram and comprising (a) about 12 to 18 parts by weight of mineral oil (b) about 24 to 30 parts by weight of tall oil (c) about 3 to 9 parts by weight of water (d) about 29 to 35 parts by weight of an alkali metal salt of an alkyl aryl sulphonic acid having a molecular weight of about 420 to 520 (e) about /2 to 7 /2 parts by weight of sulphonated oil (f) about /2 to 6 parts by weight of an alkylene glycol in which the alkylene radical has about 2 to 5 carbon atoms, and (g) about 4 to 10 parts by weight of an aliphatic alcohol having 2 to 3 carbon atoms; and (4) about 0.05 to 0.5 part by weight of an organic amine selected form the group consisting of hydroxy amines and polyoxyamines, said amines having a molecular chain composed solely of carbon, oxygen and nitrogen atoms as chain atoms, and having in addition to said chain atoms, only hydrogen atoms in its molecule.

6. An emulsifiable oil composition comprising (1) about 70 to 80 parts by weight of a mineral oil, (2) about /2 to 5 parts by weight of an alkyl phosphate having a neutralization number of about 190 to 400 milligrams of KOH per gram and in which the alkyl radical has about 1010 24 carbon atoms, (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 and 12.5 milligrams of KOH per gram and comprising (a) about 12 to 18 parts by weight of mineral oil (b) about 24 to 30 parts by weight of tall oil (0) about 3 to 9 parts by weight of water (d) about 29 to 35 parts by weight of an alkali metal salt of an alkyl aryl sulphonic acid having a molecular weight of about 420 to 520 (e) about /2 to 7 /2 parts by weight of sulphonated castor oil (f) about A to 6 parts by weight of an alkylene glycol in which the alkylene radical has about 2 to 5 carbon atoms, (g) about 4 to 10 parts by weight of an aliphatic alcohol having 2 to 3 carbon atoms; and (4) about 0.05 to 0.5 part by weight of monoethanol amine.

7. An emulsifiable oil composition comprising (1) about to parts by weight of a mineral oil, (2) about /2 to 5 parts by weight of an alkyl phosphate having .1 neutralization number of about to 400 milligrams of KOH per gram and in which the alkyl radical has about 10 to 24 carbon atoms, (3) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 to 12.5 milligrams of KOH per gram and comprising (a) about 12 to 18 parts by weight of mineral oil (b) about 24 to 30 parts by weight of tall oil (c) about 3 to 9 parts by weight of water (d) about 29 to 35 parts by weight of an alkali metal salt of an alkyl aryl sulphonic acid having a molecular weight of about 420 to 520 (e) about /2 to 7% parts by weight of sulphonated castor oil (1) about /2 to 6 parts by weight of an alkylene glycol in which the alkylene radical has about 2 to 5 carbon atoms, (g)about 4 to 10 parts by weight of an aliphatic alcohol having 2 to 3 carbon atoms, (4) about 0.05 to 0.5 part by weight of an organic amine selected from the group consisting of hydroxyamines and polyoxyamines, said amines having a molecular chain composed solely of carbon, oxygen and nitrogen atoms as chain atoms, and having in addition to said chain atoms, only hydrogen atoms in its molecule, (5) about 15 to 200 parts by weight of water, and (6) about 0.2 to 0.7 percent by weight of the water of borax.

8. An emulsifiable oil composition comprising (1) about 70 to 80 parts by weight of a mineral oil and about /2 to 5 parts by weight of an alkyl phosphate in which the alkyl groups have about 10 to 24 carbon atoms and having a neutralization number of 190 to 400 milligrams of KOH per gram dissolved therein and also having about 0.05 to 1 part by weight of monoethanolamine dissolved therein, (2) about 18 to 24 parts by weight of an emulsifier having a neutralization number between about 9.5 to 12.5 milligrams of KOH per gram and comprising (a) about 12 to 18 parts by weight of mineral oil, (b) about 24 to 30 parts by weight of tall oil, (c) about 3 to 9 parts by weight of water, (d) about 29 to 35 parts by weight of an alkali metal salt of an alkyl aryl sulphonic acid having a molecular weight of about 420 to 520, (e) about /2 to 7 /2 parts by weight of sulphonated castor oil, (I) about /2 to 6 parts by weight of diethylene glycol and, (g) about 4 to 10 parts by weight of isopropyl alcohol.

References Cited in the file of this patent UNITED STATES PATENTS 2,080,299 Benning et al. May 11, 1937 2,328,727 Langer Sept. 7, 1943 2,470,913 Bjorksten et a1 May 24, 1949 2,668,146 Cafcas et a1. Feb. 2, 1954 2,959,549 Furey Nov. 8, 1960 FOREIGN PATENTS 666,239 Great Britain Feb. 6,1952

OTHER REFERENCES Uses and Applications of Chemicals and Related Materials, Gregory (1939), p. 112, Reinhold Pub. Co.

Metalworking Lubricants, Bastian (1951), pp. 16 and 53, McGraw-Hill Book Co., Inc. 

1. AN EMULSIFIABLE OIL COMPOSITION THAT WILL INHIBIT RUSTING OF FERROUS METALS COMPRISING (1) ABOUT 70 TO 80 PARTS BY WEIGHT OF A MINERAL OIL, (2) ABOUT 1/2 TO 5 PARTS BY WEIGHT OF AN ALKYL PHOSPHATE HAVING A NEUTRALIZATION NUMBER OF ABOUT 270 TO 350 MILLIGRAMS OF KOH PER GRAM AND IN WHICH THE ALKYL RADICAL HAS ABOUT 10 TO 24 CARBON ATOMS AND (3) ABOUT 18 TO 24 PARTS BY WEIGHT OF AN EMULSIFIER HAVING A NEUTRALIZATION NUMBER BETWEEN ABOUT 9.5 TO 12.5 MILLIGRAMS OF KOH PER GRAM AND COMPRISING (A) ABOUT 10 TO 20 PARTS BY WEIGHT OF MINERAL OIL, (B) ABOUT 22 TO 32 PARTS BY WEIGHT OF TALL OIL, (C) ABOUT 1 TO 10 PARTS BY WEIGHT OF AN ALKALI METAL HYDROXIDE, (D) ABOUT 2 TO 12 PARTS BY WEIGHT OF WATER, (E) ABOUT 27 TO 37 PARTS BY WEIGHT OF AN ALKALI METAL SOAP OF AN ALKYL ARYL SUBSTITUTED ACID HAVING A MOLEUCLAR WEIGHT OF ABOUT 300 TO 600, (F) ABOUT 0.1 TO 8 PARTS BY WEIGHT OF SULPHONATED CASTOR OIL, (G) ABOUT 0.5 TO 5 PARTS BY WEIGHT OF AN ALKYLENE GLYCOL, AND (H) ABOUT 3 TO 12 PARTS BY WEIGHT OF AN ALIPHATIC ALCOHOL. 